This invention relates to an improvement of a ruler device which can be used as a guide for drawing a line on a surface of an object, chiefly a sheet of paper, or for cutting the object. Particularly, it relates to a ruler device capable of preventing positional displacement in use and ensuring a smooth sliding movement when it moves from one place to another.
In general, a ruler device of the type mentioned above is molded of a variety of materials such as plastic, wood, bamboo, metal and the like. This ruler device is, in use, plane contacted with the surface of an object on which a line is required to be drawn. In drawing a line on the surface of the object with this ruler device, it is a usual practice that the ruler device is depressed by a finger tip of a single hand from the top and a writing instrument is held by the other hand. And in that condition, a forward end of the writing instrument is moved along the edge of the ruler device.
The ruler device is point-wise depressed by the finger tip because it is difficult for the finger tip to depress the entire surface of the ruler device. Therefore, the ruler device tends to turn about the depressed portion serving as a fulcrum by force, serving as an acting point, applied to the writing instrument at a location away from the fulcrum. In order to avoid this unfavorable turn of the ruler device, the user must increase the force for depressing the ruler device. Naturally, the user gets tired.
A ruler device with a handle is also known. In practice, however, this handle is bothersome. In addition, the ruler device with a handle is difficult to be not only stored but also to be carried.
A ruler device with a slip-preventive material such as a rubber sheet attached to the back is also known. This ruler device is, in fact, good for avoiding unfavorable displacement in use but a great inconvenience is encountered when this device is to be moved from one place to another because the rubber sheet prevents a smooth movement.
Another problem involved in the conventional ruler device occurs when an object is cut with use of the ruler device. Specifically, when an object is cut, a cutter is moved along the edge of the ruler device as mentioned above. At that time, the edge of the ruler device is occasionally cut by the cutter with a result that the ruler device itself becomes unusable.
The present invention has been accomplished in view of the above-mentioned actual status and problems inherent in the prior art devices.